Microprocessors having a low-power mode and a non-low power mode are known in the art. For example, microprocessors are known where during an idle time, the microprocessor is switched to a low power mode. In the low power mode, the clock frequency is lowered relative to the clock frequency in the non-low power mode, i.e. the normal mode. However, lowering of the clock frequency affects the accuracy of the timing and scheduling of events.